Telephone recording system



4 Sheets-Sheet 1 xom mmozum C. F. FFQLLIOTT TELEPHONE RECORDING SYSTEM Filed Nov'. 5, 1,945

INVENTOR.

ATTO R NEY S on. 20.25% 553mm III: n"; 1 ||||||i Dec. 2, 194?.

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INVENTOR. CHARLES F. FFOLLlOTT Dec; 2 194? c. F. FFOLLIOTT TELEPHONE RECORDING SYSTEM Filed Nov. 5, 1943 4 Sheets-Sheet 5 won xOm 44mm iii mom

NVEN TOR. CHARLES F. FFO LLIOTT @LW ATTORNEYS Dec. 2, 1947. c.,F. FFOLLlOTT TELEPHONE RECORDING SYSTEM Filed Nov. 5, 1943 4 Sheets-Sheet 4 momscm INVENTOR.

CHARLES F. FFOLLIOTT wwv I ATTORNEYS Patented Dec. 2, 1947 UNITED STATES PATENT OFFICE TELEPHONE RECORDING SYSTEM Application November 5, 1943, Serial No. 509,027

21 Qlaims.

The present invention relates to telephone conversation recording systems. More particularly, this invention relates to the recording of telephone conversations conducted over a telephone line, and is especially adapted to making an accurate record of two-way telephone conversations which it is desired to preserve for future reference. The system is arranged to be readily associated with any telephone line, requires no metallic connections therewith, and is controllable by a subscriber to record all or parts of a telephone conversation taking place over a line and in such a manner that the party at the distant point is not advised of such recording.

Briefly, the recording system comprises two phonographic recording mechanisms, suitably controlled by sequence operation apparatus for starting and stopping each recorder at the appropriate intervals to provide continuous recording of a conversation which may extend over a period beyond the capacity of a, record, An audio-frequency amplifier is provided for the necessary amplification of speech voltages for proper operation of the respective recorders. There are also provided control switches for starting and stopping the operation of the recording mechanism and associated control and supervisory equipment. Supervisory lamp signals are provided for indicating which recorder is in operation, and for indicating when the recording system is conditioned for operation. The recording system is associated with the desired telephone line merely by placing an inductive device :in the form of a pickup coil upon the regular bell box or telephone of the telephone substation. No

alterations are required in the regular telephone circuit or its line to associate the recordin mechanism with the desired line and it is therefore readily attached to any line with a minimum of effort.

It is an object of the invention to provide a telephone conversation phonograph recording system wherein the record cutters are selected for use in alternate order and are controlled to provide an overlap period wherein b'oth recorders are recording at the same time. Another object of the invention is to provide recording apparatus of the above-mentioned type wherein sequence operation means are controlled by the cutting arms for controlling the motors of the recorders to provide for the alternate use of the recorders and the stopping of the motor which is not in use. Stil1 another object of the invention is to provide means for transmitting pulses by the operation of switching means controlled by the cutting arms to control relay switching means by which the recorder motors are appropriate'y started and stopped. It is a further object of the invention to provide a coil which is adapted to be placed in inductive relation to the induction coils of the telephone set whereby energy is received for the operation of the recorders. Another object is to provide a combined telephone conversation recording and reproducing system by which a telephone conversation may be recorded and then played back or reproduced upon the telephone line.

Other and further objects of the invention will become apparent upon reference to the following description taken in connection with the accompar ying drawings in which,

Figure 1 illustrates somewhat diagrammatically the apparatus and circuit connections of one embodiment of the invention which employs a motor-driven sequence operation mechanism for controlling the sequential operation of the two recorders;

Fig. 2 illustrates a recording system which includes a motor-driven sequence operation mechanism of modified form;

Fig. 3 illustrates a recording system in which the sequence operation mechanism employs a group of relays for controlling the sequential operation of the recorders; and

Fig. 4 shows somewhat diagrammatically the apparatus and circuit connections of a modified system capable of recording a telephone conversation and of reproducing that conversation on the telephone line.

Referring to Fig. 1 of the drawings, there is illustrated a telephone set '1, including a ringer box housing 99, a ringer I05, a condenser I05, and an induction coil H3, a transmitter I01, a receiver I68, and a hook switch H0. The hook switch H0, when operated, completes circuits for connecting the telephone set to the associated line I 00 extending by way of an exchange to a distant telephone set.

Associated with the telephone T is a pickup coil I is which is designed to pick up inductively, when placed in close proximity with the induction coil H3 of the telephone T, the conversation taking place over the line. An audio-frequency amplifier M0 is connected to the pickup coil H4 by the conductors H1, H8 and H9, and functions to amplify voice currents which have been inductively picked up and to transmit the amplified currents over the conductors H6 to a pair of phonograph recorders indicated as I20 and 30. .i

completes a circuit for energizing a sequence operation motor I 62, which drives a number of cams I5I, I54, I51 and I60 of a sequence operation mechanism I50, these cams being arranged to operate their associated springs and contacts to control certain circuit-s for regulating the recorders I 20 and I30 together with a plurality of supervisory lamps.

The recorder I30 is similar in all respects to the recorder I20 and is selected for use upon the completion of the record which has been cut by the recorder I20. This recorder I30 comprises a turntable I3 I, driven in the direction of the arrow by a motor I35 and adapted to have placed thereon a record I36 adapted to be operated upon by a cutter carried by the cutter arm I32. When the recording space of the record is nearly filled a lug I33 carried by the arm I32 closes the switch contacts I34 which are also connected in the controlling circuit of the sequence operation motor I62. A signal lamp I66 indicates when illuminated that the system is in condition to make recordings and the lamps I 61 and I68 indicate which of the recorders have been selected for use.

Considering in more detail the operation of the system, and referring to Fig. 1, the closing of the switch I65 by a subscriber at the telephone set T completes a circuit from an alternating current power supply through the conductors IOI and I02 for energizing the amplifier I40 which is thereby conditioned for use. Also, the closing of the switch I65 completes a circuit for energizing the lamp I66 to indicate that the system is ready for recording a telephone conversation. Upon the closing of the switch I63, after closing the switch I65, a circuit is prepared for both of the turntable motors I25 and I35 and for the signal lamps I61 and I68. With the apparatus in the condition illustrated, but with the switches I63 and I65 closed, the turntable motor I 25 will operate in a circuit which may be traced from the power conductor IOI by way of switches I65 and I63, through the motor I25, contacts I53 and I 56 in multiple, and back to the other power conductor I02. At the same time, the circuit of the signal lamp I6! is completed to indicate that the motor I 25 has started to operate.

In the operation of the recorder I20 to record the conversation taking place over the line I00, the voice currents conducted over the line I00 and passin through the induction coil I I3 are inductively picked up by the pickup coil I I4 and. are transmitted to the amplifier I 40 by way of the conductors ill and H8. The amplifier I40 transmits corresponding voice currents by way of the conductors I 56 to both of the cutting arms I22 and 532 in multiple. However, if, as shown, only the recorder I 26 is in operation at the time, the conver ation will be recorded only by that recorder. A conversation which extends beyond the recording capacity of a record and is to be continued on a second record will for a short period be reco ded by bo h recorders to obviate the Dossibility of omitting a part of the QQDVQ SE EiQh during the change over from one recorder to another,

Assuming that the recorder I20 is in operation and that the cutting arm I 22 has reached a point near the end of the record I26, the lug I23 causes the contacts I 24 to be engaged to close a circuit for starting the sequence operation motor I62. This circuit may be traced from the supply conductor I02 through the contacts I24 and I58 and the motor I62 to the supply conductor I 0| The sequence operation motor I62, through a reduction gear train (not shown), drives the cams I5I, I54, I51 and I60 in unison in a clockwise direction. The cam I60, upon rotating a short distance, closes at the contacts I6I in parallel with the contacts I58, and this establishes another circuit for the sequence operation motor I62, thus causing the cams I5I, I54, I51 and I60 to continue,to rotate through one half of a revolution, even though the contacts I58 are opened immediately after the revolution starts. At the conclusion of one half of a revolution of the cam I60, the contacts I6I are opened to interrupt the circuit for the motor I62 which stops the cams in positions degrees from the positions shown. The contacts I55 were also closed shortly after the cam I54 started to rotate, thereby completing a circuit for operating the turntable motor I35 and thereby driving the recorder I30, so that the conversation is then recorded by the recorder I30 while it still continues to be recorded by the recorder I20. The closing of the contacts I55 also closes the circuit of the signal lamp I68 to indicate that the recorder I30 is operating. The contacts I56 are moved into open position at the beginning of the movement of the cam I54 but the circuit of the motor I25 is maintained by the contacts I53 which do not open until the completion of a half of a revolution of the cam I5I.

-., When the circuit of the motor I25 is interrupted at the contacts I53, the signal lamp I61 is extinguished, the lamp I6I being connected in multiple with this motor.

The attendant at the recorders is advised by the condition of the lamps I 61 and I68 that the record I26 may be removed and a new record placed upon the recorder I20. In removing the record I26, the arm I22 is moved to the left which allows the contacts I24 to open and interrupt a point in the original circuit for energizing the sequence operation motor I62, which is without efi'eot at this time.

When a conversation being recorded upon the record I36 is to be continued upon the new record on recorder I20, the contacts I34 will be closed by the lug I33 shortly before the record I36 is completely filled, which completes a circuit by way of contacts I59 and the conductors MI and I02 for again starting the sequence operation motor I62. As described before, the contacts I6I are closed at the commencement of the half revolution of the cams to maintain the circuit of the motor I62 so that this motor continues to drive the associated cams through a second one half revolution during which time both recorders are in operation. The motor I25 is then energized over a circuit including the contacts I56 when the cam I 54 starts to rotate: After the cams again come to rest in the position shown, the circuit for energizing the turntable motor I35 is opened at contacts I52 and I55 to terminate the recording by the recorder I30. The signal lamp I63 is simultaneously extinguished and the lamp I6! is at the same time illuminated to indicate, respectively, the stopped and running condi ace-1,797

tions of the recorders I36 and I20. A new record may then be placed on the turntable I3I and the continued alternate operation of the recorders may be carried on as above described, with an overlap of the recording by the two recorders each time that one recorder nears the end of the operation of filling the recording space of the record mounted upon it.

A dual switch MI is provided, in the circuit shown in Fig. l, for causing the operation of both recorders to record an entire conversation simultaneously. When closed, the dual switch I4! completes circuits for both turntable motors I25 and I35. With the system in the condition illustrated. the motor I25 is operated over a circuit including contacts I56 and I53 and the motor I35 is actuated over a circuit including switches I65, I63 and MI and contacts I56 and I53 in multiple. Should the sequence operation mechanism I56 be resting in a position 180 degrees from that shown, during this dual operation, the motor I35 would be actuated over a circuit including contacts I55 and I52, while the motor I25. would be actuated in circuit with the switches I4I, I65 and I63, and the contacts 152 and I55 in multiple. During this dual operation both lamps I61 and I68 are illuminated from the supply conductors IM and I62 over a circuit including the switch I H- and the contacts I56 and I53 when the system is in the position shown, or the contacts I52 and I55, when the cams are rotated through one hundred and eighty degrees from the position shown.

Referring to Fig. 2 of the drawings, there is shown a modification of the invention in which a telephone line 266 terminates in a telephone set T A pickup coil 2 I4 is inductively associated with the induction coil 213 of the telephone T and operates to transmit the telephone conversation to an amplifier 246 over the conductors 2H and 2I8. The amplifier 246 supplies, by way of the conductors '2 I6, voice currents to operate the two phonographic recorders 226 and 236 which are connected in multiple and provided with control switches 224 and 264, respectively, for controlling a sequence operation mechanism 256.

Sequence operation mechanism 256' is provided to control the turntable motors 225 and 235 of the recorders 226 and 236', as well as the supervisory lamps 29I and 292. This sequence opera tion mechanism includes a driving motor 266, which is coupled through a speed reducing gear (not shown) to a, pair of cams 258 and 256 which are rotated in unison for operating a number of switch contacts. Power for operating the sequence operation mechanism 256 and the turnable motors is derived from a source of alternating current through the supply conductors 26I and 262. A signal lamp 296 indicates, when lighted, that the system is operating, and the signal lamps 29I and 262 indicate, respectively, that the recorders 226 and 236 are conditioned for operating. A pair of control switches 265 and 263 are provided for preparing the system for use, and for starting the turntable motor of the recorder which is conditioned to start record ing.

Considering in more detail the operation of the system shown in Fig. 2 of the drawings, the closing of the switch 265 completes an obvious cir' cuit for energ zing the amplifier 246, which is thereby conditioned for use. At the same time, one orthe other of the lamps 2! or 262 will. light depending upon which recorder is prepared to operate, and with the apparatus conditioned as illustrated, the lamp 26| is lighted over a circuit which includes the conductor 262, control switch 255, lamp. 29L contacts 252 and 253 in multiple, and the conductor 26L With the lamp '26I illuminated, the subscriber is. notified that the recorder 226 is selected to record the conversation taking place over line 266. Upon closing the switch 263. the circuit for the turntable motor 225 is completed; this circuit may be traced from the conductor 262, by way of the switches 265 and 263, through the motor 225 and contacts 252 and 253 in multiple to the conductor 26L The signal lamp 296 is also lighted when the switch 263 is operated to, closed position to indicate that the system is recording the telephone message. Voice currents conducted over the line 266 and passing through the induction coil 2E3 are inductively picked up by the pickup coil- 2I4 and are transmitted therefrom to the amplifier 246 by way of the conductors 2H and 2I 8. The amplifier 246 transmits voice currents over the conductors 2I6 to the cutting arms 222 and 232 in multiple, so that they may be recorded by either recorder 226 or 236.

A conversation which extends beyond the recording capacity of the record 226 and is to be continued upon the record 236wi11, for a short period prior to the time when the cutter reaches the end of the recording space of the record 226, be recorded upon both records. When the cutting arm 222 reaches a point near the end of the record 226, the lug 223 causes the contacts 224 to engage, and thereby close, a circuit for actuating the sequence operation motor 266. This circuit may be traced from conductor 26I, by way of the contacts 224 and 256, through the motor 26.6 and back to conductor 262. The motor 256 then operates and drives the cam 256 which, when it starts to rotate, closes the contacts 251, and thereby establishes an alternate circuit for the motor 266 which causes the cams to be driven through one half of a revolution before they are stopped. At the conclusion of one half of a revolution of the cam 259, the contacts 251 are opened to interrupt the circuit for the motor 266, and as the contacts 256 are also then disengaged, the motor 266 is stopped.

The cam 253, upon rotating 2. short distance, causes the contacts 25I to be engaged and close a circuit for the turntable motor 235, which circuit includes the conductor 26I, contacts 25I, the motor 235 and the switches 263 and 265 in series to the conductor 262. The turntable motor 235 starts and drives the recorder 236 while the recorder 226 continues to operate, the circuit for motor 225 being maintained for the duration of the half revolution of earn 258 by the closed contacts 253. When the cam 256 reaches a position approximately from that shown, the cons tacts 256 are opened to interrupt the circuit for the motor .225, which stops the recorder 226 and extinguishes the signal lamp 26L The contacts 256 are then closed to complete a multiple. circuit for continuing the actuation of the motor 235 and the lamp 262, this lamp indicating that the recorder 236 is in operation.

The attendant at the recorders is notified, by the condition of the lamps 29I and 262, that the record .226 may be removed from the recorder 226 and a new record he placed upon the turntable 229. In removing the record 226, the cutting arm 622 is moved to the left, thereby allowing the contacts 224 to be disengaged, The contacts 224, upon opening, interrupt the original circuit for the motor 266.

When a conversation being recorded upon the record 236 is to be continued upon the new record on the recorder 229, the contacts 234 will be closed shortly before the record 236 is completely filled, thereby completing a circuit by way of the contacts 255 for again actuating the sequence operation motor 260. As described before, the motor 239 drives the cams 258 and 259 one half of a revolution, during which time both recorders are in operation. The motor 225 is then actuated, when cam 258 starts to rotate, over a circuit which includes the power conductor 29!, the contacts 252, the motor 225 and the switches 263 and 265 in series to the power conductor 292. After the cams 258 and 259 again come to rest in the position shown in the drawing, the circuit for actuating the motor 235 is opened at the contacts 254, since the contacts 25! were opened when the cam 258 started to rotate. Also, the signal lamp 292 is extinguished when the motor 235 is stopped, since the lamp 292 is connected in multiple with the motor 235. The signal lamp 29! is lighted upon completion of its circuit at the contacts 252 to indicate that the recorder 220 is in operation. From this point the continued alternate operation of the recorders is the same as described above. The same overlap of recording obtains in the change-over period from the recorder 23] to the recorder 22!! as prevailed in the change from the recorder 229 to the recorder 23!], due to the fact that the contacts 252 and 254 are closed during the one half revolution of cam 258.

A dual switch 24! is provided for causing the operation of both recorders to record the conversation simultaneously. When closed, the dual switch 24! completes circuits for both of the turntable motors 225 and 235. With the system in the condition illustrated, the motor 225 is energized over a circuit including the conductor 292, the switches 265 and 263, the contacts 252 and 253 in multiple and the conductor 29!, and the motor 235 is energized over a circuit which includes the switches 255, 263 and 24! and the contacts 252 and 253 connected in multiple to the conductor 29!. Should the cams of the sequence operation mechanism 253 be resting in positions !89 from those shown, the motor 235 would be actuated over a circuit including the conductor 232, the switches 265 and 263, the contacts 25! and 254 connected in multiple to the conductor 23!. The motor 225 would be actuated over a circuit which includes the conductor 292, the switches 265, 263 and 24!, and the contacts 25! and 254 connected in multiple to the conductor 29 During this dual operation both signal lamps 29! and 292 are illuminated by circuits connected in multiple with their respectively associated motors.

Referring to Fig. 3 of the drawings, there is illustrated another modification of the invention comprising the usual telephone set 'I terminating a telephone line 309. The telephone set also includes a ringer 395. a condenser 396, a transmitter 39?, a receiver 368, a hook switch 3!0, and an induction coil 313. Associated with the telephone T is a pickup coil 3! 4 which is arranged in inductive relationship to the induction coil 3!3 to pick up a telephone conversation being conducted over the line 309, and to transmit that conversation to an amplifier 349 over the lines 3!! and 3H3. The amplifier 340 supplies, by way of conductors 3i6, voice currents to operate the two phonographic recorders 329 and 333 which are connected in multiple. The recorders 320 and 339 are provided with control switches for controlling a sequence operation mechanism 350.

The sequence operation 350 is provided to control the turntable motors 325 and 335 of the recorders 320 and 330, respectively, and also to control the supervisory or signal lamps 395, 396, 39! and 392. The sequence operation mechanism 350 includes two pairs of interlocking relays, with each pair arranged in such a manner that a first relay of a pair, when energized, operates and locks mechanically. The second relay of each pair, when operated, unlocks the mechanical lock, thereby allowing the first relay to restore.

A power supply system for furnishing the required alternating current for operation of the amplifiers 340, the turntable motors 325 and 335 and the signal lamps 395,396,390, 39! and 392, is connected to the circuits of the recording apparatus by conductors 30! and 392. An auxiliary power supply 34!, including a transformer 342 and a rectifier 343, is provided for furnishing rectified current to the relay devices in the sequence operation mechanism 350.

At the telephone set 'I is a control box which includes a power switch 365, for controlling the power to the amplifier 349 and to the lamp 390, and a motor switch 363 for controlling the power to the turntable motors 325 and 335, to the auxiliary power supply 34!, and to the signal lamps 39!, 392. The control box also includes the signal lamps 399, 39! and 392. The lamps 395 and 396 are located at the reccrding devices and are provided for the purpose of advising an attendant of the operating or restored condition of the two recorders.

' Considering in more detail the operation of the system in reference to Fig. 3 of the drawings, the closing of the switch 365 completes a circuit for energizing the amplifier 340 and the multiple connected lamp 399. Circuits are also prepared at the switch 365 for actuating the lamps 395 and 396 and, dependent upon which recorder is conditioned for use, the corresponding lamp circuit is completed. That is, when recorder 329 is selected for use, the lamp 396 will be illuminated over a circuit which includes the conductor 30!, switch 365, lamp 396, contacts 382 and the conductor 352. If, however, the recorder 33!) has been selected, the lamp 395 is lighted over a circuit including the conductor 39 switch 355, lamp 395, contacts 352 and the conductor 302.

Upon operation of the motor switch 363, circuits are completed for the auxiliary power supply 34!, and the turntable motor 325 together with the signal lamp 39 The circuit for the motor 325 extends from the conductor 33! by way of switches 355 and 363 through the motor 325 and contacts 382 to conductor 302. The lamp 39 is energized over a circuit which includes the switches 365 and 363, the contacts 384 and the power conductors 30! and 302.

Relay 380 is shown mechanically locked in an operated position whereby the recorder 320 is selected to record a telephone conversation taking place over the line 300. Voice currents conducted over the line 300 and passing through an induction coil 3!3 are inductively picked up by the pickup coil 3!4 and the amplifier 346 transmits the amplified voice currents over the conductors M6 to the cutting arms 322 and 332. However, as only the recorder 32!! is at present assumed to be in operation, the conversation will be recorded only by that recorder.

A conversation which extends over the recording capacity of the record 326, and is to be continued upon the record 336, will for a short time prior to the end of the record 326 be recorded upon both records. When the cutting arm 322 recording arm 433 and the reproducing arm 434- or" the recording and reproducing mechanism which includes a motor 436 for driving a recording turntable 43! upon which is mounted a phonograph disk 435 in the usual manner. The recording arm 433 is provided to cut a record of a telephone conversation and the reproducing arm 434 is provided for reproducing, back over the telephone line, a recorded message. It is contemplated that either of the arms may be operative during a conversational period and, by manipulation of the switch 430, either of the arms may be included in the conversational circuit.

When it is desired to record a conversation taking place over the line 400, the key 44! is closed to complete an obvious circuit for energizing the motor 436 from the source of power 438. The switch 439 is also operated to close its contacts 2 and 3 to complete a circuit, including the conductors 416 and 43!, between the amplifier 449 and the recording arm 433. The closing of the contacts 6 and I completes a circuit, including the conductors 4|! and 8, between the pickup coil M5 and the input terminals of the amplifier 440, Upon then placing the recording arm 433 upon the recording disk 435, a record may be made of any conversation taking place upon the line 400. More particularly, any voice currents that pass through the induction coil 4l3 are inductively picked up by the pickup coil 5 and are conducted over the conductors 4H and 418 through the contacts 6 and I of the switch 430 to the amplifier 440. These voice currents are therein amplified and are extended over the conductors M6 and by way of the contacts 2 and 3 of switch 430 and conductors 43! to the recording arm 433, The recording arm 433 responds to the amplified voice currents to record the conversation upon the disk 435.

When it is desired to reproduce upon the telephone line 400 the conversation recorded on the disk 435, the switch 430 is operated to cause the contacts 2, 3, 5 and I to become disengaged from the movable switch contacts and thus open the recording circuits, and to cause the contacts I, 4, 5 and 8 to be closed to complete the reproducin circuits, which include the reproducing arm 434, the battery or power supply 442, the amplifier 440 and the coil 425. The reproducing arm 434 is energized by the battery 442, and when the arm is placed upon the disk 435, it effectively transmits by way of the conductors 432 and the contacts 5 and 8 of the switch 430, corresponding voice currents to the amplifier 440. The amplifier 440 functions to increase the amplitude of these voice currents and transmits them over conductors 4H; and by way of the contacts I and 4 of the switch 430 and the conductors M9 and 420 to the coil 425. Responding to the amplified Voice currents, the coil 425 creates an inductive field whereby the induction coil M3 is inductively affected to reproduce corresponding voice currents upon the line 400.

From the foregoing it will be seen that at the option of the operator a telephone conversation may be recorded upon a, phonograph record or the recorded conversation may be reproduced upon the line, whereby both parties may hear the record, and, further, the recording mechanism may be excluded from the connection entirely by operating the switch 430 to its neutral position.

Although several forms of the invention have been shown and described by way of illustration,

it will be understood that the invention may be constructed in various other embodiments which come within the scope of the appended claims.

I claim:

1. A telephone conversation. phonograph recording system comprising, a pickup coil adapted to be positioned in inductive relation to the induction coils of a telephone set, an amplifier connected to said pickup coil, a pair of record cutters energized by said amplifier, a turntable and motor for each cutter, a source of power for said amplifier and said motors, a switch for each turntable adapted to be actuated by said cutter as it approaches the end of a record, and means controlled by said switch for energizing the other motor from said source or" power before the end of a record is reached to provide an overlap period wherein both cutters are recording at the same time.

2. A telephone conversation phonograph recording system comprising, a pickup coil adapted to be positioned in inductive relation to the induction coils of a telephone set, an amplifier connected to said pickup coil, a pair of record cutters energized by said amplifier, a turntable and motor for each cutter, a source of power for said amplifier and said motors, a switch for each turntable adapted to be actuated by said cutter as it approaches the end of a record, and sequence operation means controlled by said switch for energizing the other motor prior to the end of a record to provide an overlap period wherein both cutters are recording at the same time and for deenergizing the first motor when the end of the first record is reached.

3. A telephone conversation recording system comprising, a pickup coil adapted to be positioned in inductive relation to the induction coils of a telephone set, a pair of record cutters energized in response to energy received by said ickup coil, a record carrying turntable and a motor for each cutter, a switch for each turntable adapted to be actuated by its cutter as it approaches the end of a record, and sequence operation means controlled by said switches for energizing and deenergizing said motors thereby to provide prior to the end of a record an overlap period wherein both cutters are recording at the same time and for deenergizing each motor at the end of the recording on the record carried on the turntable driven thereby.

4. A telephone conversation phonograph recording system comprising, a pickup coil adapted to be positioned in inductive relation to the induction coils of a telephone set, an amplifier connected to said pickup coil, a pair of record cutters energized by said amplifier, a turntable and motor for each cutter, a switch for each turntable adapted to be actuated by said cutter as it approaches the end of a record, said switch having two sets of contacts one of which closes before the other, and sequence operation means controlled by one set of contacts of said switch for energizing the other motor prior to the end of a record to provide an overlap period wherein both cutters are recording at the same time, and means including said other set of switch contacts for deenergizing the first motor at the end of the first record.

5. A telephone conversation phonograph recording system comprising, a pickup coil adapted to be positioned in inductive relation to the induction coils of a telephone set, means for making records in accordance with the energy received by said pickup coil including apair of some:

record cutters, a turntable and motor for each cutter, a switch for each turntable arranged to be actuated by said cutter as it approaches the end of a record, a pair of interlocking relays for each of said motors to control the operation thereof, the first of each pair of relays having certain contacts locked into position upon energ'izati'on of said relay, the second of each pair of relays operating to release the contacts of said first relay, said switch having contacts connected to one relay of each pair of relays, said relays operating' to energize the other motor prior to the end of a record to provide an overlap recording period and to deenergize the other motor at the end of the record.

6. A tele hone conversation recording system comprising, a picku'p coil adaptedto bepositioned in inductive relation to the induction coils of a telephone set, a pair of record cutters energized in response to the energyreceive'd by said pickup coil, a turntable and motor for each record cutter, a Switch for each turntable adapted to be actuated by its record cutter as it approaches the end of a record, said switch means each on eratingtc transmit two current impulses, one im' pulse prior to the completion of a record and an other impulse at the completion of a record, and means responsive to said pulses for energizing the other motor prior to the end of a record to provide an overlap recording period and for deenergizing the one motor at the'end of its record.

7. A telephone conversation recording system comprising, a pickup coil adapted to be placed in inductive relation to the induction coils of a telephone set, means for producing a record in accordance with the energy received by said coil including a pair of record cutters, a turntable and motor for each cutter, a switch for each turntable adapted to be actuated by its cutter as it approaches the end of a record, and sequence operation means controlled bysaid switches for controlling the operation of said turntable motors including a sequence operation motor connected to a plurality of groups of cam operated switches, one of said groups of cam operated switches operating to energize both turntable motors prior to the end of a record to provide an overlap recording period and to stop one turntable motor when the end of a record has been reached, and another group of cam operated switches operating to switch the control of said sequence operation motor' from one turntable switch to the other turntable switch near the end of the record.

8. A telephone conversation recording system comprising, a pickup coil adapted to be placed in inductive relation to the induction coils of a telephone set,rmeans for producing a record in accordance with the energy received by said coil including a pairof record cutters, a turntable and motor for each cutter, a switch for each turntable adapted to be actuated by its cutter as it approaches theendof a record, and sequence operation means controlled by said switches for controlling the operation of said turntable motors including a sequence operation motor connected to a plurality of groups of cam operated switches, one of said groups of cam operated switches operating to energize both turntable motors prior to the end ofa record to provide an overlap recording period and to stop one turntable motor when the end of a record has been reached, and another group of cam operated switches operating to switch the control of said sequence operation motor from one turntable switch to the other turntable switch near the end of the rec- 14 0rd, and a manually operable switch for causing both turntable motors to be operated at the same time.

9. A telephone conversation recording system comprising, a pickup coil adapted to be placed in inductive relation to the induction coils of a telephone set, means for producing a record in accordance with the energy received by said pickup coil including a pair of record cutters, a turntable and motor for each cutter, a source of power, a power switch for connecting certain of said equipment to saidsource to condition said equipment for operation, a second power switch connected between said source and said motors, a switch for each turntable adapted to be actuated by its cutter as it approaches the end of a rec= 0rd, sequence operation means controlled by said switches for determining the operation of said turntable motors including a sequence operation motor connected to a plurality if groups of cam operated switches, one of said groups of cam operated switches operating to energize both turntable motors prior to the end of a record to provide an overlap recording period, another group of said cam operated switches operating to switch the control of said sequence operation motor from one turntable switch to the other turntable switch near the end of a record, and a third set of cam operated switches preparing a visual signal system to indicate which motor will start first upon actuation of said second power switch.

10. A telephone conversation recording system comprising, a pickup 'coil adapted to be placed in inductive relation to the induction coils or a telephone set, means forproducing a record in accordance with the energy received by said pickup coil including apair of record cutters, a turntable and motor for each cutter, a source of power, a power switch for connecting certain of said equipment to said source to condition said equipment for operation, a second power switch connected between said source and said motors, a switch for each turntable adapt-ed to be actuated by its cutter as it approaches the end of a record, sequence operation means controlled by said switches for determining the operation of said turntable motors including a sequence operation motor'connected to a plurality of groups of cam operated switches, one of said groups of cam operated switches operating to energize both turntable motors prior tothe end of a record to provide an overlap recording period, another group of said cam operated switches operating to switch the control of said sequence operation motor from one turntable switch to the other turntable switch near the end of a record, and a third set of cam operated switches, a signal circuit including said third set of camoperated switches for indicating that said equipment is being conditioned for operation when said first power switch is actuated and for indicating which turntable motor is operated when said second power switch is actuated.

11. A telephone conversation recording system comprising, a pickup coil adapted to be placed on the exterior of a telephone set in inductive relation to the induction coils of said telephone set, means including an amplifier-for producing a record in accordance with the energy received by said pickup coil including a pair of record cutters, a turntable and motor for each cutter, a source of power, a power switch for connecting said amplifier to said source, a second power switch interconnecting said source and said turntable motors, a switch for each turntable adapted to be actuated by its cutter as it approaches the end of a record, sequence operation means controlled by said turntable switches for controlling the said sequence operation means including a sequence operation motor connected to a plurality of groups of cam operated switches, one of said groups of cam operated switches operating to control the operation of said turntable motors and to energize both turntable motors prior to the end of a record to provide an overlap recording period near the end of a record on one of said turntables, another group of said cam operated switches operating to change the control of said sequence operation motor from one turntable switch to the other turntable switch as the cutter aproaches the end of a record, a third set of cam operated switches being adapted to control a signal light system, a signal circuit including said third set of cam operated switches and a plurality of signal lights for indicating which motors are being energized,

12. In a system for recording telephone conversation at a telephone subscriber station including a telephone set having an induction coil, the combination of means for producing a record in accordance with a telephone conversation, and means for receiving energy from the telephone set to control the actuation of said first-named means, said second-named means comprising a coil adapted to be placed on the outside of said telephone set in inductive relation to the induction coil of said telephone set.

13. The combination with a telephone set having an induction coil of a telephone conversation recording and reproducing system comprising, a pickup coil adapted to be positioned in inductive relation to said induction coil, an amplifier arranged to be connected to said pickup coil, a record cutter energized by said amplifier, a turntable for supporting a record in operative relation to said cutter, a motor for driving said turntable, a reproducing device arranged to be operated by a record on said turntable, power supply means for said amplifier and said reproducing device, and means for controlling the operation of said cutter and said reproducing device.

14. The combination with a telephone set having an induction coil of a telephone conversation recording and reproducing system comprising, a pickup coil adapted to be positioned in inductive relation to said induction coil, an amplifier arranged to be connected to said pickup coil, a record cutter energized by said amplifier, a turntable for supporting a record in operative relation to said cutter, a motor for driving said turntable, a reproducing device arranged to be operated by a record on said turntable, power supply means for said amplifier and said reproducing device, means for controlling the operation of said cutter and said reproducing device, and a second pickup coil arranged to be connected in the circuit with said reproducing device and said amplifier and adapted to be placed in inductive relation to said induction coil.

15. In a sound recording system the combination comprising at least two recording machines for recording sounds on records, means controlled by each machine for starting another machine when the record of the former is substantially full, means controlled by each machine for stopping it a predetermined period of time after it has started another machine, a first control for starting and stopping an operating machine, and a second control for connecting the first control to two or more machines whereby duplicate records of the same dictation may be made.

16. In the combination of 15, means also controlled by each machine for transferring the first control to each machine as it is started by another.

17. In an electro-acoustic system the combination including a recording machine having a rotatable record support, a recording head for cooperating with the record when mounted on said support, driving means for causing relative movement between said support and recording head, a power circuit for said driving means, a control station remote with respect to said recording machine, a microphone, circuits interconnecting the microphone with the recording head, a marking control switch at the control station for partially completing said power circuit, and a start-stop switch at the control station for completing the power circuit to said driving means.

18. In an electro-acoustic system the combination including a, recording machine having a rotatable record support, a recording head for cooperating with the record when mounted on said support, driving means for causing relative movement between said support and recording head, a power circuit for said driving means, a control station remote with respect to said recording machine, a microphone, circuits interconnecting the microphone with the recording head, a marking control switch at the control station for partially completing said power circuit, a start-stop switch at the control station for completing the power circuit to said driving means, a signal lamp at the control station, and a circuit completed by the operation of the marking control switch to indicate that the machine is ready for recording.

19. In an electro-acoustic machine of the type described the combination including a rotatable record support, a sound recording head, driving means for causing relative movement between said support and head, drive control means for controlling the starting and stopping of said driving means including a start-stop switch, a power circuit for said drive control means, and a marking control switch for partially completing said power circuit, successive operation of said start-stop switch causing successive energization of said driving control means to cause the starting and stopping of the machine.

20. In an electro-acoustic machine of the type described the combination including a rotatable record support, a sound recording head, driving means for causing relative movement between said support and head, drive control means for controlling the starting and stopping of said driving means including a start-stop switch, a power circuit for said drive control means, a marking control switch for partially completing said power circuit, successive operation of said start-stop switch causing successive energization of said drive control means to cause the starting and stopping of the machine, a signal lamp, and a power circuit for said lamp completed when said marking control switch is first operated.

21. A system for controlling the operation of a dictation machine, including a movable record support, a recording head, a reproducing head, said heads being independently engageable with a record on said support, a single manual means remote with respect to said machine controllable only for starting and for stopping it, and a single manual means at the remote point controllable only for rendering either the recording head or the reproducing head operfile of this patent: 2,261,420

18 UNITED STATES PATENTS Name Date Paulas July 14, 1925 Zullo Dec. 10, 1929 Keiser Sept. 11, 1934 Keiser June 25, 1935 Whitehead et a1. May 14, 1940 Shiveley et a1 Nov. 4, 1941 

